From d30dc9abb4aacfd4df3f486f22bcbc0531b73283 Mon Sep 17 00:00:00 2001 From: Alexey Starikovskiy Date: Sun, 30 Sep 2007 22:39:36 +0400 Subject: ACPICA: hw: remove use_lock flag from acpi_hw_register_{read, write} use_lock flag is used once for acpi_hw_register_read, and never for acpi_hw_register_write. It will greatly simplify understanding of locking if we just drop this use_lock altogether, and wrap the only call to ..._read in lock/unlock. Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/hardware/hwregs.c | 89 ++++++++++++++++------------------------- drivers/acpi/hardware/hwsleep.c | 27 +++++-------- 2 files changed, 44 insertions(+), 72 deletions(-) (limited to 'drivers/acpi/hardware') diff --git a/drivers/acpi/hardware/hwregs.c b/drivers/acpi/hardware/hwregs.c index 1d371fa..73f9c5f 100644 --- a/drivers/acpi/hardware/hwregs.c +++ b/drivers/acpi/hardware/hwregs.c @@ -75,8 +75,7 @@ acpi_status acpi_hw_clear_acpi_status(void) lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock); - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1_STATUS, + status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS, ACPI_BITMASK_ALL_FIXED_STATUS); if (ACPI_FAILURE(status)) { goto unlock_and_exit; @@ -259,7 +258,7 @@ struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id) * ******************************************************************************/ -acpi_status acpi_get_register(u32 register_id, u32 * return_value) +acpi_status acpi_get_register_unlocked(u32 register_id, u32 * return_value) { u32 register_value = 0; struct acpi_bit_register_info *bit_reg_info; @@ -276,8 +275,7 @@ acpi_status acpi_get_register(u32 register_id, u32 * return_value) /* Read from the register */ - status = acpi_hw_register_read(ACPI_MTX_LOCK, - bit_reg_info->parent_register, + status = acpi_hw_register_read(bit_reg_info->parent_register, ®ister_value); if (ACPI_SUCCESS(status)) { @@ -298,6 +296,16 @@ acpi_status acpi_get_register(u32 register_id, u32 * return_value) return_ACPI_STATUS(status); } +acpi_status acpi_get_register(u32 register_id, u32 * return_value) +{ + acpi_status status; + acpi_cpu_flags flags; + flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock); + status = acpi_get_register_unlocked(register_id, return_value); + acpi_os_release_lock(acpi_gbl_hardware_lock, flags); + return status; +} + ACPI_EXPORT_SYMBOL(acpi_get_register) /******************************************************************************* @@ -335,8 +343,7 @@ acpi_status acpi_set_register(u32 register_id, u32 value) /* Always do a register read first so we can insert the new bits */ - status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK, - bit_reg_info->parent_register, + status = acpi_hw_register_read(bit_reg_info->parent_register, ®ister_value); if (ACPI_FAILURE(status)) { goto unlock_and_exit; @@ -363,8 +370,7 @@ acpi_status acpi_set_register(u32 register_id, u32 value) bit_reg_info-> access_bit_mask); if (value) { - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1_STATUS, + status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS, (u16) value); register_value = 0; } @@ -377,8 +383,7 @@ acpi_status acpi_set_register(u32 register_id, u32 value) bit_reg_info->access_bit_mask, value); - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1_ENABLE, + status = acpi_hw_register_write(ACPI_REGISTER_PM1_ENABLE, (u16) register_value); break; @@ -397,15 +402,13 @@ acpi_status acpi_set_register(u32 register_id, u32 value) bit_reg_info->access_bit_mask, value); - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1_CONTROL, + status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL, (u16) register_value); break; case ACPI_REGISTER_PM2_CONTROL: - status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM2_CONTROL, + status = acpi_hw_register_read(ACPI_REGISTER_PM2_CONTROL, ®ister_value); if (ACPI_FAILURE(status)) { goto unlock_and_exit; @@ -430,8 +433,7 @@ acpi_status acpi_set_register(u32 register_id, u32 value) xpm2_control_block. address))); - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM2_CONTROL, + status = acpi_hw_register_write(ACPI_REGISTER_PM2_CONTROL, (u8) (register_value)); break; @@ -461,8 +463,7 @@ ACPI_EXPORT_SYMBOL(acpi_set_register) * * FUNCTION: acpi_hw_register_read * - * PARAMETERS: use_lock - Lock hardware? True/False - * register_id - ACPI Register ID + * PARAMETERS: register_id - ACPI Register ID * return_value - Where the register value is returned * * RETURN: Status and the value read. @@ -471,19 +472,14 @@ ACPI_EXPORT_SYMBOL(acpi_set_register) * ******************************************************************************/ acpi_status -acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value) +acpi_hw_register_read(u32 register_id, u32 * return_value) { u32 value1 = 0; u32 value2 = 0; acpi_status status; - acpi_cpu_flags lock_flags = 0; ACPI_FUNCTION_TRACE(hw_register_read); - if (ACPI_MTX_LOCK == use_lock) { - lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock); - } - switch (register_id) { case ACPI_REGISTER_PM1_STATUS: /* 16-bit access */ @@ -491,7 +487,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value) acpi_hw_low_level_read(16, &value1, &acpi_gbl_FADT.xpm1a_event_block); if (ACPI_FAILURE(status)) { - goto unlock_and_exit; + goto exit; } /* PM1B is optional */ @@ -507,7 +503,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value) status = acpi_hw_low_level_read(16, &value1, &acpi_gbl_xpm1a_enable); if (ACPI_FAILURE(status)) { - goto unlock_and_exit; + goto exit; } /* PM1B is optional */ @@ -523,7 +519,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value) acpi_hw_low_level_read(16, &value1, &acpi_gbl_FADT.xpm1a_control_block); if (ACPI_FAILURE(status)) { - goto unlock_and_exit; + goto exit; } status = @@ -558,10 +554,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value) break; } - unlock_and_exit: - if (ACPI_MTX_LOCK == use_lock) { - acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags); - } + exit: if (ACPI_SUCCESS(status)) { *return_value = value1; @@ -574,8 +567,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value) * * FUNCTION: acpi_hw_register_write * - * PARAMETERS: use_lock - Lock hardware? True/False - * register_id - ACPI Register ID + * PARAMETERS: register_id - ACPI Register ID * Value - The value to write * * RETURN: Status @@ -597,28 +589,22 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value) * ******************************************************************************/ -acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value) +acpi_status acpi_hw_register_write(u32 register_id, u32 value) { acpi_status status; - acpi_cpu_flags lock_flags = 0; u32 read_value; ACPI_FUNCTION_TRACE(hw_register_write); - if (ACPI_MTX_LOCK == use_lock) { - lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock); - } - switch (register_id) { case ACPI_REGISTER_PM1_STATUS: /* 16-bit access */ /* Perform a read first to preserve certain bits (per ACPI spec) */ - status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1_STATUS, + status = acpi_hw_register_read(ACPI_REGISTER_PM1_STATUS, &read_value); if (ACPI_FAILURE(status)) { - goto unlock_and_exit; + goto exit; } /* Insert the bits to be preserved */ @@ -632,7 +618,7 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value) acpi_hw_low_level_write(16, value, &acpi_gbl_FADT.xpm1a_event_block); if (ACPI_FAILURE(status)) { - goto unlock_and_exit; + goto exit; } /* PM1B is optional */ @@ -647,7 +633,7 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value) status = acpi_hw_low_level_write(16, value, &acpi_gbl_xpm1a_enable); if (ACPI_FAILURE(status)) { - goto unlock_and_exit; + goto exit; } /* PM1B is optional */ @@ -661,11 +647,10 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value) /* * Perform a read first to preserve certain bits (per ACPI spec) */ - status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1_CONTROL, + status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL, &read_value); if (ACPI_FAILURE(status)) { - goto unlock_and_exit; + goto exit; } /* Insert the bits to be preserved */ @@ -679,7 +664,7 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value) acpi_hw_low_level_write(16, value, &acpi_gbl_FADT.xpm1a_control_block); if (ACPI_FAILURE(status)) { - goto unlock_and_exit; + goto exit; } status = @@ -728,11 +713,7 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value) break; } - unlock_and_exit: - if (ACPI_MTX_LOCK == use_lock) { - acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags); - } - + exit: return_ACPI_STATUS(status); } diff --git a/drivers/acpi/hardware/hwsleep.c b/drivers/acpi/hardware/hwsleep.c index cf69c00..4d0c677 100644 --- a/drivers/acpi/hardware/hwsleep.c +++ b/drivers/acpi/hardware/hwsleep.c @@ -313,8 +313,7 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state) /* Get current value of PM1A control */ - status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1_CONTROL, &PM1Acontrol); + status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL, &PM1Acontrol); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); } @@ -341,15 +340,13 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state) /* Write #1: fill in SLP_TYP data */ - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1A_CONTROL, + status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL, PM1Acontrol); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); } - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1B_CONTROL, + status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL, PM1Bcontrol); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); @@ -364,15 +361,13 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state) ACPI_FLUSH_CPU_CACHE(); - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1A_CONTROL, + status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL, PM1Acontrol); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); } - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1B_CONTROL, + status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL, PM1Bcontrol); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); @@ -392,8 +387,7 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state) */ acpi_os_stall(10000000); - status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1_CONTROL, + status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL, sleep_enable_reg_info-> access_bit_mask); if (ACPI_FAILURE(status)) { @@ -520,8 +514,7 @@ acpi_status acpi_leave_sleep_state(u8 sleep_state) /* Get current value of PM1A control */ - status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1_CONTROL, + status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL, &PM1Acontrol); if (ACPI_SUCCESS(status)) { @@ -543,11 +536,9 @@ acpi_status acpi_leave_sleep_state(u8 sleep_state) /* Just ignore any errors */ - (void)acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1A_CONTROL, + (void)acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL, PM1Acontrol); - (void)acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK, - ACPI_REGISTER_PM1B_CONTROL, + (void)acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL, PM1Bcontrol); } } -- cgit v1.1 From 2d571b33cf7efd6a894e765e3cb45587ec5b834a Mon Sep 17 00:00:00 2001 From: Alexey Starikovskiy Date: Sun, 30 Sep 2007 22:39:42 +0400 Subject: ACPICA: hw: Don't carry spinlock over suspend ACPI uses acpi_get_register() in order to get into suspend. This function is guarded by acpi_gbl_hardware_lock, which will be carried into resume phase. At resume interrupts are enabled and first ACPI interrupt deadlocks on this lock. Solution seems to be to not lock register read, as there are no concurrent activity at this point. Reference: http://bugzilla.kernel.org/show_bug.cgi?id=7499 Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown --- drivers/acpi/hardware/hwsleep.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/acpi/hardware') diff --git a/drivers/acpi/hardware/hwsleep.c b/drivers/acpi/hardware/hwsleep.c index 4d0c677..c0577ca 100644 --- a/drivers/acpi/hardware/hwsleep.c +++ b/drivers/acpi/hardware/hwsleep.c @@ -398,7 +398,8 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state) /* Wait until we enter sleep state */ do { - status = acpi_get_register(ACPI_BITREG_WAKE_STATUS, &in_value); + status = acpi_get_register_unlocked(ACPI_BITREG_WAKE_STATUS, + &in_value); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); } -- cgit v1.1